Fuel-based power plants contribute a significant amount of the total power generation in the U.S. In fact, a large portion of electricity produced in the U.S. comes from power plants that burn coal. In addition to coal, power plants are fired by fuels such as natural gas and petroleum. This significant generation of power by fuel-based power plants is facilitated by large-scale power generation equipment, which operates in extreme conditions for extended periods of time. These power plants are subject to strict guidelines, restrictions, and performance parameters. Therefore, power plant equipment and machinery must be meticulously maintained to ensure guideline compliance, operational efficiency, and safety.
One important task in maintaining power plant equipment is ensuring the integrity of the lubricating oil in power plant equipment. As these pieces of equipment are subject to extended periods of high stress use, the lubricating oil is therefore subject to a significant amount of contamination. For example, forced draft fans are large mechanical fan units used in the combustion system of a power plant to force oxygen into the boiler of the combustion system. The normal operation of these forced draft fans results in suspended contaminants in the lubricant oil of the bearing housing and drive units of the forced draft fans. The suspended contaminants may include quantities of sulfur, iron, copper, chromium, lead, aluminum, silicon, sodium, molybendum, tin, and silver. The contaminants and solids in suspension in the lubricant oil may be abrasive to the machinery in the forced draft fan unit. These contaminants must be regularly filtered from the lubricant oil or the oil must be replaced.
While it is important to maintain the integrity of the lubricant oil in the power plant machinery, it is also important to minimize the downtime that may result from the service of that machinery. Thus, it is advantageous to be able to service the equipment of the power plant in the vicinity of that equipment in order to minimize or even eliminate the downtime of the equipment and increase the efficiency of the filtration process.
Conventional methods by which to filter oil in the vicinity of the equipment to be serviced are typified in various U.S. patents, including U.S. Pat. No. 1,829,173 to Wertz., U.S. Pat. No. 2,425,848 to Vawter, U.S. Pat. No. 5,076,856 to Schweiger, U.S. Pat. No. 5,597,601 to Griffin, U.S. Pat. No. 6,247,325 to Muston, U.S. Pat. No. 5,091,085 to Thalmann, U.S. Pat. No. 5,395,514 to Siegler, U.S. Pat. No. 5,160,722 to Hochella, U.S. Pat. No. 6,138,722 to Willingham, U.S. Pat. No. 1,962,463 to Renfrew, U.S. Pat. No. 4,702,827 to Wenzel, and U.S. Pat. No. 5,062,500 to Miller et al. For instance, U.S. Pat. No. 1,829,173 to Wertz discloses a flushing device and lubricant dispenser adapted for cleaning and flushing automotive transmissions. The patent discloses a wheeled device with a tank, a pump, an intake pipe for the pump, and a discharge conduit having a injector. The device is a wheeled device, which utilizes a rotary pump “10” and an injector “16” to pump flushing oil into the transmission and create suction in a discharge line. In accordance with the disclosure, the device is also provided with a means for filtering and separating solid particles from the diluted lubricant removed from the transmission.
U.S. Pat. No. 2,425,848 to Vawter discloses a flushing and filtering unit for use in cleaning moving or working parts in machinery. The disclosed device has a tank for holding flushing oil or lubricant, a pump, filters, and connecting conduits. The unit is capable of circulating fluid having contaminating material in suspension and filtering the contaminating material from the fluid. The majority of the embodiments disclosed involve circulating a flushing oil through a piece of machinery and then filtering the collected dirt and solid material from the flushing oil.
U.S. Pat. No. 5,076,856 to Schweiger discloses a method for removing contaminated oil and contaminants from heat exchangers. In one embodiment, an apparatus is used which provides a pump, filter canisters, and conduits on a wheeled frame. The method disclosed involves using the apparatus to pump solvent through a heat exchanger in a direction opposite the normal direction of flow; stopping the flow of solvent for a period of time; flowing air under pressure through the heat exchanger in a direction opposite the normal flow; pumping oil through the heat exchanger in the normal direction of flow; stopping the flow; and subsequently flowing air under pressure in the normal direction.
U.S. Pat. No. 5,597,601 to Griffin discloses an apparatus and process for on-site filtering of the cooking oil of a deep fat fryer. The apparatus disclosed includes a chasis mounted on casters containing an auxiliary reservoir “22”, canisters “96”, filters “112”, an input suction line “150”, a pump “148”, and a dispensing hose “90”. The apparatus is used to filter solid particles from the cooking oil of a deep fat fryer vat at the location of the vat, by draining the oil from the vat, pumping the oil through renewable filter elements, and then dispensing the cleaned oil back into the vat.
U.S. Pat. No. 6,247,325 to Muston et al. discloses an apparatus for servicing a refrigeration system. In one disclosed embodiment, the apparatus consists of a support frame having wheels mounted on its lower end. Multiple chambers are mounted within the housing means of the apparatus, including an accumulator chamber, condenser chamber, high and low pressure filter chambers, and a fluid control means. The apparatus is disclosed as enabling flow between these chambers to facilitate the removal or return of refrigerant. In one embodiment the filter provided is an annular filter “70”, which serves to filter out water molecules or droplets from the refrigerant. The apparatus is disclosed as enabling service of a refrigerant system without loss of the refrigerant agent to the atmosphere.
U.S. Pat. No. 5,091,085 to Thalmann et al. discloses a ultrafiltration device to be used in filtering waste water. The unit includes a prefilter, a pump, a membrane filter cartridges containing membrane elements, a temperature sensor means, a pressure sensor means, and a process interdiction and control means, which are all mounted to a wheeled support frame.
In one embodiment, the circulating pump “22” moves waste water through an input line “15” and through the filtration membrane of cartridge “26”, enabling the oil or other larger molecule liquid to be filtered from the water.
U.S. Pat. No. 5,395,514 to Siegler discloses an ultrafiltration device for the separation of water from mixtures with larger molecule liquids. Siegler discloses a device which incorporates, a centrifugal pump, membrane filter cartridges, an eductor means, a return means, a waste outlet, and a means for controlling the device. The patent discloses a device that pumps waste mixtures at a high pressure through an ultrafiltration membrane with a centrifugal pump; thereby, separating water from larger molecule liquids, such as oils, coolants, and antifreeze, to obtain water with less than 50 ppm of larger molecule contaminant.
U.S. Pat. No. 5,160,722 to Hochella et al. discloses a method for the catalytic oxidation of ammonia in which the catalyst used is a gauze material of wire mesh. The disclosed method involves passing the ammonia through this wire mesh to convert and oxidize the ammonia into nitric acid. In the embodiments disclosed, the wire mesh filter has a specifically delineated curve to flat ratio in relation to the mesh count per inch and wire diameter.
U.S. Pat. No. 6,138,722 to Willingham discloses an apparatus for reconditioning the drivetrain unit fluid of a motor vehicle. In one embodiment, Willingham provides a portable apparatus which contains a hose “12” with an extraction tube “30” and a discharge tube “34”, a pump “14”, and a filter “16”. The apparatus enables extraction of the drivetrain unit fluid from the drivetrain unit. The fluid may then be transmitted to the pump, pressurized by the pump and caused to pass through the filter, and then propelled back into the drive train unit.
U.S. Pat. No. 1,962,463 to Renfrew discloses an apparatus for removing impurities from insulating and lubricating oils to restore the efficiency of the oil. The apparatus provides an electric motor, multiple pumps, a filter, and lines for receiving and distributing oil. The device is enabled to connect with a device containing contaminated oil, pump the oil from the device, pass the oil under pressure through the filter, vacuum the oil to the discharge ends, and return the liquid to the serviced device.
U.S. Pat. No. 4,702,827 to Wenzel discloses a filter for cooking apparatus including a power supply, filter operation mode, pump, wand, heater, and control circuitry. The device disclosed in Wenzel addresses a problem encountering with previous portable filters used in cleaning cooking oil fryers. The patent discloses that many of the conventional devices provide an independent heating element to be used in heating the oil to a liquid flowable temperature, and these heating elements pose a fire hazard. The Wenzel device discloses a portable filter apparatus configured with switching means to intelligently disable the heating element of the apparatus during dangerous modes of operation.
U.S. Pat. No. 5,062,500 to Miller et al. discloses a low profile cart for the collection, filtration, and recycle of fluid from machinery. The low profile cart is equipped with a fluid receiving chamber, a pump, a filter, and a means for manually positioning the cart. The cart is provided with a low profile so as to be enabled to be placed underneath a piece of machinery, such as a vehicle or farm equipment. Thereby, the fluid containers of the machinery may drain directly into the chamber of the filter device.
While suitable for their intended purposes, the filtration systems and methods of the prior art are, for the most part, large, heavy, and bulky. Even though many are provided on wheeled carts, their portability is limited. The filtration machines of the prior art are not lightweight or compact, much less capable of being carried by a user. Furthermore, many of the prior art machines incorporate a reservoir to hold either new, discharged, or contaminated fluid. The reservoir significantly limits the portability and capability of the filtration system.
Additionally, the problem encountered in the conventional methods and systems of filtering the lubricant oil of power plant machinery and equipment arises from the need to take the equipment out of operation for extended periods of time in order to service the equipment. This is an especially large problem with power plant equipment, which may remain in operation for lengthy time periods. For example, the problem encountered in the conventional method of filtering the lubricant oil of forced draft fans arises from the need to take the forced draft fans out of operation for extended periods of time in order to remove the fan to access the lubricant oil contained in the bearing housing and drive unit of the forced draft fan. Both the service time required to perform this operation and the inoperability associated with the service are highly costly to the power plant. What is needed, therefore, is an apparatus or system that is capable of servicing the power plant equipment either without taking the equipment out of service or with minimal downtime to that equipment.
Furthermore, a filtration system is highly desired that is capable of filtering the lubricating oil of power plant machinery without creating cavitation in the lubricating oil of the machinery. Cavitation due to filtration results when either air or vapor bubbles form in lubrication oil as a result of the filtering process and are subsequently emploded in the either the machinery or the filtering pump by the pressurized oil. This leads to microjets of oil pounding and eroding adjacent surfaces, thus deteriorating the filtering equipment and the machinery being serviced.
The methods and systems and disclosed in the prior art do not teach a filtering device capable of overcoming the known problems. Therefore a need exists for a system that will enable users to overcome the problems of the prior art and allow users to efficiently and effectively service and recondition the lubricant oil of power plant machinery.